This previous commit

  commit cd9fcc8b
  Author: Michal Privoznik <mprivozn@redhat.com>
  Date:   Wed Jul 27 16:58:32 2016 +0200

    libvirt.spec.in: Adapt to newest wireshark plugindir

Adapted the libvirt spec for wireshark >= 2.1.0 but
this ignored the fact that we enable wireshark from
Fedora 21 and 2.1.0 was only added in Fedora 24
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>